In electrophysiological diagnostic procedures such as intracardiac electrical mapping, an invasive medical probe is introduced into a cavity of a body organ. As the probe is positioned at specific points within the organ, the probe measures specific information (e.g., an electrical potential) and conveys the measurements to a mapping system. The mapping system creates a map comprising the measurements at their respective locations in the organ. The map can be used in applying various diagnostic and therapeutic procedures to the organ.
When placing the probe within the organ, it may be desirable to have the distal tip of the probe in direct contact with organ tissue. The contact can be verified, for example, by measuring the contact pressure between the distal tip and the tissue. U.S. Patent Application Publications 2007/0100332, 2009/0093806 and 2009/0138007, whose disclosures are incorporated herein by reference, describe methods of sensing contact pressure between the distal tip of a catheter and tissue in a body cavity using a force sensor embedded in the catheter.